This invention generally relates to assembly of machines, and more particularly it relates to automated assembly and inspection of split shell bearing inserts as used in internal combustion engine crankshafts or the like.
In reciprocating engines, for example, the crankshafts are normally supported by main bearings which are of the split shell type. In addition, the connecting rod to crankpin journals on the crankshaft also have similar bearings.
When these machines are assembled, it is important to assure that there are no defects in the bearing to crankshaft assembly. These defects include missing bearing inserts, oversize inserts, undersize inserts, oversize bearing bores, and undersize bearing bores. Oversize bearing housing bore and undersize bearing housing bore and/or undersize inserts and oversize inserts can lead to a loose or tight bearing fit to the engine block or connecting rod. In any case, the machine would experience early failure due to bearing fit defect or missing bearing.
At present, a common method of inspecting for these defects is to visually examine during the assembly for the presence of the bearing insert. It is also common for tightening values of the fasteners to be checked automatically at time of assembly. Torque values by themselves do not give indication that bearing shells are installed or indication of problem bearing fit. This method, therefore, has the disadvantage of requiring a secondary operation for inspection after assembly. A disadvantage of visual inspection is the difficulty of seeing the edges of the assembled bearing in the crankshaft assembly. This may make detection of a missing insert very difficult and time-consuming.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.